Efficient immobilization of cellulase on polydopamine-modified nickel foam for enhanced lignocellulose conversion

In situ saccharification of lignocellulose is essential for efficiently converting biomass into value-added products. In this study, nickel foam underwent electrochemical pore size regulation and polydopamine modification to produce polydopamine-modified foam nickel with aperture control (PNiF-AC), which was used for cellulase immobilization and in situ saccharification of wheat straw. PNiF-AC demonstrated excellent hydrophilicity, biocompatibility, and robust adsorption-desorption cycling properties. Immobilizing cellulase onto PNiF-AC significantly improved its thermal stability by 64.8 %. The immobilized cellulase yielded 17.0 mg/mL of reducing sugars during the in situ saccharification of wheat straw, representing a 20 % increase over free cellulase. Moreover, after eight cycles of magnetic stirring, the reducing sugar yield decreased by only 19.4 %, highlighting the remarkable reusability and stability of the immobilized cellulase. These findings establish polydopamine-modified foam nickel as an efficient platform for cellulase immobilization, presenting a novel approach to improving lignocellulose conversion processes.